/*
* FreeRTOS+TCP <DEVELOPMENT BRANCH>
* Copyright (C) 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* http://aws.amazon.com/freertos
* http://www.FreeRTOS.org
*/
/**
* @file FreeRTOS_ICMP.c
* @brief Implements the Internet Control Message Protocol for the FreeRTOS+TCP network stack.
*/
/* Standard includes. */
#include <stdint.h>
#include <stdio.h>
#include <string.h>
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"
/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_IP_Private.h"
#include "FreeRTOS_ICMP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_ARP.h"
#include "FreeRTOS_UDP_IP.h"
#include "FreeRTOS_DHCP.h"
#include "NetworkInterface.h"
#include "NetworkBufferManagement.h"
#include "FreeRTOS_DNS.h"
/*
* Turns around an incoming ping request to convert it into a ping reply.
*/
#if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )
static eFrameProcessingResult_t prvProcessICMPEchoRequest( ICMPPacket_t * const pxICMPPacket,
const NetworkBufferDescriptor_t * const pxNetworkBuffer );
#endif /* ipconfigREPLY_TO_INCOMING_PINGS */
/*
* Processes incoming ping replies. The application callback function
* vApplicationPingReplyHook() is called with the results.
*/
#if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
static void prvProcessICMPEchoReply( ICMPPacket_t * const pxICMPPacket );
#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
#if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
/**
* @brief Process an ICMP packet. Only echo requests and echo replies are recognised and handled.
*
* @param[in,out] pxNetworkBuffer The pointer to the network buffer descriptor
* that contains the ICMP message.
*
* @return eReleaseBuffer when the message buffer should be released, or eReturnEthernetFrame
* when the packet should be returned.
*/
eFrameProcessingResult_t ProcessICMPPacket( const NetworkBufferDescriptor_t * const pxNetworkBuffer )
{
eFrameProcessingResult_t eReturn = eReleaseBuffer;
iptraceICMP_PACKET_RECEIVED();
configASSERT( pxNetworkBuffer->xDataLength >= sizeof( ICMPPacket_t ) );
if( pxNetworkBuffer->xDataLength >= sizeof( ICMPPacket_t ) )
{
/* Map the buffer onto a ICMP-Packet struct to easily access the
* fields of ICMP packet. */
/* MISRA Ref 11.3.1 [Misaligned access] */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
/* coverity[misra_c_2012_rule_11_3_violation] */
ICMPPacket_t * pxICMPPacket = ( ( ICMPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
switch( pxICMPPacket->xICMPHeader.ucTypeOfMessage )
{
case ipICMP_ECHO_REQUEST:
#if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )
{
eReturn = prvProcessICMPEchoRequest( pxICMPPacket, pxNetworkBuffer );
}
#endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) */
break;
case ipICMP_ECHO_REPLY:
#if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
{
prvProcessICMPEchoReply( pxICMPPacket );
}
#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
break;
default:
/* Only ICMP echo packets are handled. */
break;
}
}
return eReturn;
}
#endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 ) */
/*-----------------------------------------------------------*/
#if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )
/**
* @brief Process an ICMP echo request.
*
* @param[in,out] pxICMPPacket The IP packet that contains the ICMP message.
* @param pxNetworkBuffer Pointer to the network buffer containing the ICMP packet.
* @returns Function returns eReturnEthernetFrame.
*/
static eFrameProcessingResult_t prvProcessICMPEchoRequest( ICMPPacket_t * const pxICMPPacket,
const NetworkBufferDescriptor_t * const pxNetworkBuffer )
{
ICMPHeader_t * pxICMPHeader;
IPHeader_t * pxIPHeader;
uint32_t ulIPAddress;
pxICMPHeader = &( pxICMPPacket->xICMPHeader );
pxIPHeader = &( pxICMPPacket->xIPHeader );
/* HT:endian: changed back */
iptraceSENDING_PING_REPLY( pxIPHeader->ulSourceIPAddress );
/* The checksum can be checked here - but a ping reply should be
* returned even if the checksum is incorrect so the other end can
* tell that the ping was received - even if the ping reply contains
* invalid data. */
pxICMPHeader->ucTypeOfMessage = ( uint8_t ) ipICMP_ECHO_REPLY;
ulIPAddress = pxIPHeader->ulDestinationIPAddress;
pxIPHeader->ulDestinationIPAddress = pxIPHeader->ulSourceIPAddress;
pxIPHeader->ulSourceIPAddress = ulIPAddress;
/* Update the TTL field. */
pxIPHeader->ucTimeToLive = ipconfigICMP_TIME_TO_LIVE;
/* The stack doesn't support fragments, so the fragment offset field must always be zero.
* The header was never memset to zero, so set both the fragment offset and fragmentation flags in one go.
*/
#if ( ipconfigFORCE_IP_DONT_FRAGMENT != 0 )
pxIPHeader->usFragmentOffset = ipFRAGMENT_FLAGS_DONT_FRAGMENT;
#else
pxIPHeader->usFragmentOffset = 0U;
#endif
#if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
{
/* calculate the IP header checksum, in case the driver won't do that. */
pxIPHeader->usHeaderChecksum = 0x00U;
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0U, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), uxIPHeaderSizePacket( pxNetworkBuffer ) );
pxIPHeader->usHeaderChecksum = ( uint16_t ) ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );
/* calculate the ICMP checksum for an outgoing packet. */
( void ) usGenerateProtocolChecksum( ( uint8_t * ) pxICMPPacket, pxNetworkBuffer->xDataLength, pdTRUE );
}
#else
{
/* Just to prevent compiler warnings about unused parameters. */
( void ) pxNetworkBuffer;
/* Many EMAC peripherals will only calculate the ICMP checksum
* correctly if the field is nulled beforehand. */
pxICMPHeader->usChecksum = 0U;
}
#endif /* if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 ) */
return eReturnEthernetFrame;
}
#endif /* ipconfigREPLY_TO_INCOMING_PINGS == 1 */
/*-----------------------------------------------------------*/
#if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
/**
* @brief Process an ICMP echo reply.
*
* @param[in] pxICMPPacket The IP packet that contains the ICMP message.
*/
static void prvProcessICMPEchoReply( ICMPPacket_t * const pxICMPPacket )
{
ePingReplyStatus_t eStatus = eSuccess;
uint16_t usDataLength, usCount;
uint8_t * pucByte;
/* Find the total length of the IP packet. */
usDataLength = pxICMPPacket->xIPHeader.usLength;
usDataLength = FreeRTOS_ntohs( usDataLength );
/* Remove the length of the IP headers to obtain the length of the ICMP
* message itself. */
usDataLength = ( uint16_t ) ( ( ( uint32_t ) usDataLength ) - ipSIZE_OF_IPv4_HEADER );
/* Remove the length of the ICMP header, to obtain the length of
* data contained in the ping. */
usDataLength = ( uint16_t ) ( ( ( uint32_t ) usDataLength ) - ipSIZE_OF_ICMPv4_HEADER );
/* Checksum has already been checked before in prvProcessIPPacket */
/* Find the first byte of the data within the ICMP packet. */
pucByte = ( uint8_t * ) pxICMPPacket;
pucByte = &( pucByte[ sizeof( ICMPPacket_t ) ] );
/* Check each byte. */
for( usCount = 0; usCount < usDataLength; usCount++ )
{
if( *pucByte != ( uint8_t ) ipECHO_DATA_FILL_BYTE )
{
eStatus = eInvalidData;
break;
}
pucByte++;
}
/* Call back into the application to pass it the result. */
vApplicationPingReplyHook( eStatus, pxICMPPacket->xICMPHeader.usIdentifier );
}
#endif /* if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 ) */
/*-----------------------------------------------------------*/